Changing the frequencies with rovlock in powerstates 1 or 2 doesn't seem to have any effect on power consumption at all. No matter what I do, I always get the same ~1220 mA current drawn from my battery (state 1). Only if I go to low with the frequency, I get a system hang. Maybe it's insignificant then, in undervolted state frequency doesn't matter too much.

ATI's PowerPlay not only undervolts and underclocks, if you have PCI express, it also disables PCI-lanes (at least windows drivers do so). I've read that the 16 lanes PCIexpress in normal state provides consume something around 6-7W (!). 6 W@12V -> 200mA extra current ... and somehow this number was familiar to me. I've noticed a strange fluctuation in power consumption, sometimes the current my notebook needs switches down to ~1000mA ... compared to the number above, this could just be my PCIexpress. I never noticed any change in system performance this fluctuation was related to, nor did I switch off any components, nor was it related to harddisk or fan activity. The only noticeable thing was some extra heat.
Could it be that switching off PCI lanes is somehow "unstable"? And something tries to re-enable them? Where can I find system information about my PCI express?_________________Treffen sich zwei Planeten.
Sagt der eine: "Oh, gehts mir schlecht! Ich hab homo sapiens!"
Antwortet der andere: "Keine Angst, das kenn' ich. Geht schnell vorbei!"

I get the same "invalid reference clock from BIOS: 0.0 MHz" when I ran rovclock -i on my Radeon x1900GT. I think that it might have something to do with the kernel not fully recognizing the GPU ("unknown device 724b")

I have an ATI Radeon Mobility 7500 in my laptop, ChipID 0x4C57, with 32MB shared RAM. Compaq crippled the BIOS in this thing, so I can't change the amount of RAM shared to video without doubling the amount of RAM in the computer. I haven't been able to find a decent group of settings for overclocking this video card. Can anyone share their wisdom on this?

You see, instead of arguing from ignorance, and fear, there is only one way to verify a theory. And that's not by clutching a black book and begging the sky fairy for deliverance from the mad scientists and their big machines.

I get the same "invalid reference clock from BIOS: 0.0 MHz" when I ran rovclock -i on my Radeon x1900GT. I think that it might have something to do with the kernel not fully recognizing the GPU ("unknown device 724b")

I believe the output of lspci does not rely on the kernel, but on /usr/share/misc/pci.ids

This gives me a great performance boost with (so far) good stability. Tweaking beyond this results in artifacts, distortion, loss of performance, and sometimes even rebooting. I've gone from ~647fps to ~1018 in glxgears and can now use compositing without worry. Yay!_________________

aidanjt wrote:

You see, instead of arguing from ignorance, and fear, there is only one way to verify a theory. And that's not by clutching a black book and begging the sky fairy for deliverance from the mad scientists and their big machines.